Portable water purifier with ultraviolet light source

ABSTRACT

A portable container is disclosed, provided a means for the purification of a fluid by ultraviolet radiation. The container houses the liquid and mates with the ultraviolet light source, which is powered by a battery attached thereto. Additionally, an ultraviolet light sensor is provided to shut off the ultraviolet light and notify the user when the water has received an adequate dose of ultraviolet radiation.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 09/601,817, filedAug. 8, 2000, now U.S. Pat. No. 6,514,405, which is a U.S. NationalPhase Application of PCT/US99/18355, filed Aug. 12, 1999, which claimspriority from U.S. Provisional Patent Application Ser. No. 60/096,260,filed Aug. 12, 1998. The entire contents of which are incorporatedherein by reference.

The present invention relates generally to a water purificationapparatus and, more particularly, to a portable water purifying andgermicidal disinfecting system that utilizes ultraviolet radiation toprepare water for human consumption.

BACKGROUND OF THE INVENTION

Natural water supplies can be contaminated by any number ofdisease-carrying microorganisms from bacteria to protozoa to viruses.Consuming water that contains these organisms can lead to cramps,vomiting, diarrhea and even more serious medical problems. For water tobe safe to drink, these microorganisms must be either rendered inactiveor removed.

There exists a need for portable water treatment systems for providingwater suitable for human consumption at remote locations. This needexists, for example, in rural areas where sophisticated water treatmentfacilities are not present, and in the aftermath of disasters such asearthquakes and hurricanes where the local water supply has beencontaminated or disrupted. While enjoying recreational activities ofextended periods of time, such as hiking or camping, there is a need forwater to be purified in relatively small quantities. In these instances,some effective method of treating local water supplies becomesnecessary.

Various devices have been developed to disinfect water using irradiationof infected water with certain frequencies of electromagnetic radiationsuch as those in the ultra-violet range. U.S. Pat. No. 4,849,100 issuedto Papandrea discloses a portable water purifier which shuts off thewater flow therethrough upon sensing that the ultraviolet lightintensity has fallen below a predetermined level, in an attempt toensure that all of the water is sufficiently purified. U.S. Pat. No.4,755,292 issued to Merriam discloses a portable ultraviolet watersterilizer with ultraviolet reflective sidewalls, in an attempt toshield the user from harmful ultraviolet radiation and cause the waterto be efficiently exposed to ultraviolet light.

The devices used heretofore have generally proved to be unsatisfactoryfor one or more reasons. Most irradiation water purification deviceshave been designed to remain stationary, having the water flow throughas it is exposed to ultraviolet light, and thus require the use of apump. Certain apparatuses of this type become coated with materialsopaque to ultraviolet light after repeated use, and thus preventssatisfactory disinfection. Other devices do not provide a sufficientduration or intensity of ultraviolet light to fully disinfect the water.Many of the portable devices fail to provide a sufficient amount ofultraviolet light, as to do so might cause the ultraviolet bulb tooverheat and become inoperable. Other devices have relied on thetendency of ultraviolet light to catalyze the formation of ozone fromoxygen. However, these devices require a great deal of power to beconsumed, and if portable, a bulky power source to be attached.

A portable water system must be compact, lightweight, and convenient touse. In addition to these requirements, a portable water purificationsystem must be effective in purifying water to a suitable quality. It isalso desirable that such a system not require the addition of chemicalsand the like to be added to the water which either may lessen thequality of the treated water or require additional supplies.

High levels and prolonged exposure to ultraviolet light has been shownin recent years to cause various skin cancers, defects relating to humaneyes, and the breakdown of human deoxyribonucleic acid. Therefore, it isdesirable for the ultraviolet radiation utilized by the device to beprevented from escaping the device and effecting those who wish tobenefit from the device's water purification.

A number of portable ultraviolet water purification devices haveattempted to fulfill this need. U.S. Pat. No. 4,849,100 issued toPapandrea discloses a portable water purifier which shuts off the waterflow therethrough upon sensing that the ultraviolet light intensity hasfallen below a predetermined level, in an attempt to ensure that all ofthe water is sufficiently purified. U.S. Pat. No. 4,755,292 issued toMerriam discloses a portable ultraviolet water sterilizer withultraviolet reflective sidewalls, in an attempt to shield the user fromharmful ultraviolet radiation and cause the water to be efficientlyexposed to ultraviolet light. However, these devices fall short ofproviding an efficient, durable, convenient, reliable portablepurification device for drinking water. For example, the Merriam deviceis not shaped to be carried but is more of a bucket, the light sourcedoes not secure or seal to the container, the container does not seal,and there is no provision for cooling the light source. The Papandreadevice requires water to flow therethrough making it poorly suited toportable use.

SUMMARY OF THE INVENTION

These problems of past devices have been overcome by the presentinvention, a portable water purification system. The portable waterpurification system of the present invention includes a container inwhich water is to be placed. Attached to the container is an ultravioletlight source which irradiates the water, the inside surfaces of the topand side portions of the container are coated with an ultravioletreflective material. The entire container is made of a material opaqueto ultraviolet light. A battery is provided in order to provide power tothe ultraviolet light source. Additionally, a sensor is provided inorder to determine when the water being purified has received anadequate dose of ultraviolet radiation. Upon this determination theoperator of the purification device is notified and the ultravioletlight source of the present invention is automatically shut off.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention will be had uponreference to the following detailed description when read in conjunctionwith the accompanying drawings, wherein like reference characters referto like parts throughout the several views, and in which:

FIG. 1 is an elevated view of a first preferred embodiment of thepresent invention;

FIG. 2 is an elevated view of a second preferred embodiment of thepresent invention; and

FIG. 3 is an elevated exploded view of an alternative embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

First referring to FIG. 1, a portable liquid purification systemaccording to the present invention is there shown. The portable liquidpurification system 10 includes a container surface 12, which generallydefines the boundaries of a liquid container 11. Water, or anotherliquid intended for human consumption may be poured into the container11. A lid 14 is then placed on the container 11 so as to seal thepurification system 10 from being in liquid communication with itssurroundings.

An ultraviolet light source 18 is removably secured to the bottom of thecontainer surface 12 in order to provide the liquid inside the container11 with ultraviolet radiation. The ultraviolet radiation is provided byan ultraviolet bulb (not shown in FIG. 1) of a type well known to thoseskilled in the art, an integral component of the ultraviolet lightsource 18. The ultraviolet bulb may be a deuterium lamp, or ahigh-pressure gas-filled arc lamp containing argon, xenon, or mercury,as is known in the art. The ultraviolet bulb may be powered by abattery, AC adapter, or solar cell (also not shown in FIG. 1).

A portable power source, either contained in the container or to whichthe container can be attached, for the activation of the irradiationsystem. Said power source may be of a rechargeable nature or of use byconventional batteries.

The ultraviolet bulb is contained in the ultraviolet light source 18 bya lens 22 and a source wall 20. The lens 22 is generally transparentwith respect to ultraviolet light, and may be formed from quartz, fusedsilica, or a high tensile plastic resistant to discoloration anddegradation. Preferably the container 11 does not have a bottom wall,but instead the source 18 seals off the bottom of the container when itis inserted into the recess 24. This provides the benefit of allowingheat from the source 18 to conduct directly to the liquid in thecontainer, thereby cooling the source. The lack of a bottom wall alsoallows a user to thoroughly clean the inside of the container 11 whenthe source is removed, thereby removing buildup from the inner surface.As is clear to those of skill in the art, there are many ways in whichthe source 18 may be sealed to the bottom of the container 11. Forexample, it may snap into place and seal off the bottom. When the source18 is removed, a cover may be provided for sealing the bottom of thecontainer 11 so that water may be sterilized and stored without tying upthe source. In this way, the source 18, may be used with multiplecontainers. Alternatively, the container may have atransparent-to-ultraviolet bottom wall so that the container 11 willbold a liquid when the source 18 is removed without the need for acover. Either way, because ultraviolet radiation passes from the source,through the lens 22, and into the container 11, the ultravioletradiation generated by the ultraviolet bulb is allowed to effect theliquid in the container 11.

The container surface 12, as well as the source wall 20, aresubstantially opaque to ultraviolet radiation. Additionally, the devicewill preferably shutoff, or not turn on, if the lid 14, also made of amaterial substantially opaque with respect to ultraviolet light, is notsecured to the container surface 12. These characteristics protect theuser from harmful ultraviolet radiation, which has been shown, insubstantial doses, to deteriorate human health.

In order to increase efficiency, a reflective coating 16 is providedalong the inner surface of container surface 12. The reflective coating16 is substantially reflective with respect to ultraviolet light so asto cause the liquid in the container to absorb a maximum amount of theultraviolet radiation emitted by the ultraviolet bulb. The reflectivecoating may be prescribed by industry standards and meet the requisitesof being a material with a relatively high reflective index, arelatively cheap material and able to be manufactured in bulkquantities.

With reference now to FIG. 2, a second purification system 10 accordingto the present invention is there shown. This embodiment is similar tothat illustrated in FIG. 1. However, this embodiment additionallyincludes an ultraviolet sensor 26. The ultraviolet sensor 26 determineswhen a sufficient amount of ultraviolet radiation has been emitted tothe liquid for the liquid to be safe for consumption. Upon making such adetermination, the ultraviolet sensor 26 preferably causes theultraviolet bulb to stop emitting ultraviolet light. Additionally, oralternatively, the user is notified in some manner that the purificationof the liquid has been completed. A sensor may be embedded into a wallof the container. Sensor may contain a transducer that converts radiantenergy into an electrical signal, which can then be quantified formeasurement. Sensor will be employed as a positive indicator that thelevel of irradiation within the container has met predeterminedrequirements. For this purpose, the sensor may include an indicator 27.This ultraviolet sensor 26 may be a photovoltaic cell, phototube,photomultiplier tube, or silicon diode, as is well known in the art.Obviously, the sensor 26 may be used with other embodiments of thepresent invention. As is known to those of skill in the art, the outputof an ultraviolet light source 18 may degrade over time due to aging.Also, the amount of ultraviolet reaching the liquid may drop if thetransparency of the lens 22 drops or sedimentation occurs. The sensor 26allows a user to compensate for this effect and to make sure the liquidis ready to drink. As the light source 18 ages, the sensor will takelonger to trigger, thereby increasing the useful life of the source 18.It also avoids over use of the light source 18, preventing prematurebattery discharge.

FIG. 2 also shows that the ultraviolet light source 18, as well as thebottom portion of the container surface 12 may be threaded so as toallow the ultraviolet light source 18 to be screwed into abutment withthe container surface 12. Obviously, the ultraviolet light source 18 mayalso be removed in an opposite manner. This screw together arrangementis an alternative to the snap together arrangement of FIG. 1. The screwtogether arrangement works well for containers with circular crosssections, as shown, but would be unsuitable for a container with anelliptical cross section. Another preferred embodiment of the presentinvention has an elliptical cross section to make the container easierto wear on a user's belt. Other shapes are also possible.

Yet another embodiment of the present invention is illustrated in FIG.3. In this embodiment, the ultraviolet bulb 28 protrudes into thecontainer 11 where the liquid is housed. The ultraviolet bulb issurrounded by a lens 22 similar to that of the first two embodiments, ofan appropriate shape.

The configuration displayed in FIG. 3, as well as similar configurationswhich fall in the scope of the present invention, allow for greater heattransfer between the ultraviolet bulb 28 and the liquid housed withinthe container 11. Ultraviolet bulbs of the type utilized in thisinvention may become very hot during operation and burn out. Byproviding a greater surface area of contact between the lens 22 andultraviolet bulb 28, and the liquid, the ultraviolet bulb, will beallowed to cool more easily, and thus avoid burning out. Additionally,the container surface 12 may be formed from a substantially thermalconductive material to indirectly allow the ultraviolet bulb 28 to becooled more efficiently.

Additionally, though not shown in the figures, a mechanical filter of atype well known to those skilled in the art may be attached to thecontainer surface where the liquid is initially poured into thecontainer 11. In this manner, particulate contaminants may be removedprior to irradiation by ultraviolet light.

Ultraviolet light can act as a catalyst in the formation of ozone fromoxygen molecules, readily available in ambient air. Ozone, likeultraviolet light, is an effective water sterilizing agent. Therefore,by allowing air to come into contact with the liquid being purified byultraviolet radiation, the sterilizing action of ozone may also beutilized.

Having described my invention, however, many modifications thereto willbecome apparent to those skilled in the art to which it pertains withoutdeviation from the spirit of the invention as defined by the scope ofthe appended claims.

I claim:
 1. A portable liquid purification system comprising: acontainer having a surface defining an interior volume, said containerhaving a bottom with a recess defined therein and a top including aopening for introducing liquid into the interior volume; an ultravioletlight source comprising a housing having an upper surface that is atleast partially transparent to ultraviolet light, said source configuredto be inserted into said recess such that said source is disposedsubstantially within said recess, said source further comprising a powersupply disposed within said housing and an ultraviolet light bulbdisposed within said housing and selectively powered by said powersupply, said source being selectively operable to project ultravioletlight through said upper surface and into said interior volume; and anultraviolet light sensor disposed on said surface of said container suchthat a portion of the ultraviolet light passing through said interiorvolume is detected by said sensor, said sensor having an indicatoroperable to indicate when a predetermined quantity of ultraviolet lighthas been detected by said sensor such that the liquid in the containerhas received a predetermined dose of ultraviolet light.
 2. The portableliquid purification system according to claim 1, wherein said source isdisk shaped and said upper surface is generally flat.
 3. The portableliquid purification system according to claim 1, wherein said containeris generally cylindrical and said bottom comprises an end of saidcylindrical container and has a diameter, said recess extending acrosssubstantially the entire diameter of said bottom.
 4. The portable liquidpurification system according to claim 1, wherein said recess is open tosaid interior volume such that said upper surface of said source is incontact with said interior volume and said source seals said bottom ofsaid container.
 5. The portable liquid purification system according toclaim 1, further comprising a rigid, liquid impermeable materialreflective of ultraviolet light lining the inside of said container. 6.The portable liquid purification system according to claim 1, saidcontainer being formed from a material generally opaque to ultravioletlight.
 7. The portable liquid purification system according to claim 1,wherein said upper surface of said housing comprises a transparent lens,the remainder of said housing being generally opaque to ultravioletlight.
 8. The portable liquid purification system according to claim 1,wherein said recess includes threads and said housing includes threadssuch that said housing threadingly engages said recess.
 9. The portableliquid purification system of claim 1, wherein said ultraviolet lightsource extends into said container such that said source is immersed inliquid during operation and is in thermal contact with the liquid.